ABSTRACT
The progress of the COVID-19 pandemic profoundly impacts the health of communities around the world, with unique effects on colleges and universities. Here, we examined the prevalence of SARS-CoV-2 in 1808 asymptomatic individuals on a university campus in California, and compared for the first time the performance of CRISPR- and PCR-based assays for large-scale virus surveillance. Our study revealed that there were no COVID-19 cases in our study population in May/June of 2020. Using the same methods, we demonstrated a substantial shift in prevalence approximately one month later, which coincided with changes in community restrictions and public interactions. This increase in prevalence, in a young and asymptomatic population, indicated the leading wave of a local outbreak, and reflected the rising case counts in the surrounding county. Our results substantiate that large, population-level asymptomatic screening using CRISPR- or PCR-based assays is a feasible and instructive aspect of the public health approach within large campus communities.
ABSTRACT
Management of the COVID-19 pandemic requires widespread SARS-CoV-2 testing. A main limitation for widespread SARS-CoV-2 testing is the global shortage of essential supplies, among these, RNA extraction kits. The need for commercial RNA extraction kits places a bottleneck on tests that detect SARS-CoV-2 genetic material, including PCR-based reference tests. Here we propose an alternative method we call PEARL (Precipitation Enhanced Analyte RetrievaL) that addresses this limitation. PEARL uses a lysis solution that disrupts cell membranes and viral envelopes while simultaneously providing conditions suitable for alcohol-based precipitation of RNA, DNA, and proteins. PEARL is a fast, low-cost, and simple method that uses common laboratory reagents and offers comparable performance to commercial RNA extraction kits. PEARL offers an alternative method to isolate host and pathogen nucleic acids and proteins to streamline the detection of DNA and RNA viruses, including SARS-CoV-2.
ABSTRACT
The COVID-19 pandemic has created massive demand for widespread, distributed tools for detecting SARS-CoV-2 genetic material. The hurdles to scalable testing include reagent and instrument accessibility, availability of highly-trained personnel, and large upfront investment. Here we showcase an orthogonal pipeline we call CREST (Cas13-based, Rugged, Equitable, Scalable Testing) that addresses some of these hurdles. Specifically, CREST pairs commonplace and reliable biochemical methods (PCR) with low-cost instrumentation, without sacrificing detection sensitivity. By taking advantage of simple fluorescence visualizers, CREST allows for a binary interpretation of results. CREST may provide a point- of-care solution to increase the distribution of COVID-19 surveillance.
